The proposed research combines basic and applied laboratory studies with clinical and educational approaches to provide new information about the basic abilities of the tactile system and the design and evaluation of tactile aids for speech perception by deaf persons. In basic studies, the temporal properties of the tactile system are outlined using amplitude-modulated stimuli and masking paradigms with vibratory stimulus presentation. Knowledge of these temporal abilities, in addition to their basic research interest, should prove useful for the design of effective tactile aids. In applied laboratory, clinical and educational trials, three different types of experimental tactile aids will be evaluated. First, studies will continue with a single-channel vibrotactile aid worn on the chest by very young deaf children, to determine whether the aid will improve their ability to attend to and produce sounds. Second, a binaural two-channel earmold vibratory stimulator will be tested with adults for its potential as a speech aid, both alone and as part of a hybrid auditory-tactile aid. Finally, the effectiveness of multichannel (16 or more) vibratory aids in improving the understanding of speech and the accuracy of a child's own speaking will be evaluated with deaf children enrolled in the CID school. Information from these studies should determine the situations in which each type of aid might be useful, and also point out needed improvements in the design of each kind of aid.